Method and system for estimation of mobile station velocity in a cellular system based on geographical data

Abstract

A system and method for estimating velocity of a mobile station in a wireless communication system using time-frequency signal processing and a geographical database. The geographical database is used for prediction of ray trajectory and ray power to provide an estimate of propagation delay associated with database points.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation-in-part application of U.S. patent application Ser. No. 12 / 848,572, filed Aug. 2, 2010, now U.S. Pat. No. 8,131,312 which in turn is a continuation-in-part application of U.S. patent application Ser. No. 12 / 786,173, filed May 24, 2010, now U.S. Pat. No. 8,200,244 both of which are incorporated in their entirety herein by reference.FIELD OF THE INVENTION[0002]The present invention relates generally to environmental modeling, and in particular to calibration of an environmental model using wireless signals.BACKGROUND OF THE INVENTION[0003]Accurate location of mobile terminals, e.g. mobile telephones, in a wireless system, for example, a cellular telephone communication system, has been a difficult challenge. Several techniques have been proposed and partially developed to address this problem, but there remains a need for a technique with greater precision of location. It is generally desirable that such a...

AI Technical Summary

Benefits of technology

The patent text describes a system and method for accurately locating mobile terminals in a wireless communication system using wireless signals. The technical effects of the invention include improved accuracy of location and reduced cost by using existing infrastructure and not disrupting operation of the communication system. The invention also takes into account the changing environment in which the mobile terminals operate, making the modeling process more accurate. The invention can be used in various wireless systems such as cellular telephone communication systems.

Problems solved by technology

Accurate location of mobile terminals, e.g. mobile telephones, in a wireless system, for example, a cellular telephone communication system, has been a difficult challenge.

Prediction of received signal strength of signals from mobile terminals that may be operating in actual environments may be a difficult task.

A source of difficulty may be a lack of available information about a propagation environment, at least in a precision that may be required for an accurate application of a theory of wave propagation, e.g. electromagnetic wave theories presented by James Clerk Maxwell.

This lack of information may be inherent in a modeling problem as a propagation environment may be changing dynamically, and also may be random in nature.

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